An earth moving apparatus such as a loader/backhoe is relatively small and is extensively used in the construction industry. The backhoe of such an apparatus is used for digging trenches and the like. Such an apparatus is typically provided with support arms which extend outwardly from opposite sides of a frame to support the apparatus during operation of the backhoe. Each support arm is connected at its inner end to the frame and is provided with a stabilizer pad at its distal end to facilitate stabilization of the apparatus during operation of the backhoe.
Each support arm is vertically movable about its connection to the frame between raised and lowered positions under the influence of a linearly distendable driver. The driver typically includes an oversized hydraulic cylinder capable of developing the force necessary to facilitate stabilization of the apparatus. The oversized cylinder extends above and generally parallel to the support arm. A cylinder end of the driver is usually connected to the frame of the apparatus and a piston-rod end of the driver is connected near the distal end of the support arm.
To enhance the versatility of the loader/backhoe, some stabilizer pads are movable between alternate positions. Such reversible stabilizer pads facilitate supporting the loader/backhoe on ground surfaces of different textures. A reversible stabilizer pad is typically provided with a resilient support surface on one side for supporting the loader/backhoe on rigid, non-resilient ground surfaces, i.e., asphalt, concrete, etc., and a flanged support surface on the other side for supporting the loader/backhoe on a more yielding ground surface, i.e., gravel, sand, loose dirt, etc.
In view of its intended use, the stabilizer pad is constructed for ruqged and abusive treatment. To readily allow reversal between alternate positions, the stabilizer pad is connected to a distal end of the support arm for pivotable rotation through about 180 degrees.
As will be appreciated, and depending on the texture of the ground surface, the operator of the earth moving apparatus forcefully moves the stabilizer pad about its pivot between alternate positions without significant concern for damage to the pad or to the apparatus as a whole. The stabilizer pad is configured with a generally U-shaped design allowing for free rotation about its connection to the support arm so that one or the other support surface may engage the ground surface.
The U-shaped design of the reversible stabilizer pad includes a cross-member extending laterally across the support arm. When the stabilizer pad is forcibly rotated such that the flanged support surface of the pad is arranged to engage the ground surface, the cross-member on the stabilizer pad presents a problem. The problem results from the cross-member on the stabilizer pad hitting and causing damage to the piston-rod end of the driver. Because of its forceful movement between positions, contact between the stabilizer pad and piston-rod end of the driver typically results in sufficient damage to the driver to require replacement of the oversized driver.
Another problem with reversible stabilizer pads has been observed when the support arm is moved to its fully raised position. With the support arm in a fully raised position, the stabilizer pad rotates about its connection to the support arm and has a tendency to assume an improper posture when the support arm is returned to a lower position. The improper posture of the stabilizer pad forces the operator to temporarily cease operation and properly orientate the stabilizer pad.
A proposed solution to these problems is to configure the support arm with a stationary stopping surface which engages and limits stabilizer pad movement. Notably, not all loader/backhoes are equipped with reversible stabilizer pads. Those loader/backhoes not so equipped do not require a limit stop for the stabilizer pad provided thereon. As will be appreciated, to manufacture and stock different support arms dependent on the type of stabilizer pad to be associated therewith is problematical and costly.
Another proposed solution involves the provision of a stop at the distal end of the support arm. It is known to provide a stop which includes a lever with a stop pin transversely extending therefrom. The lever extends outwardly from and is welded to the support arm. The stop pin extends from a free end of the lever and is positioned in the path of the stabilizer pad for preventing complete 360-degree rotation thereof.
In addition to its weight, the momentum of the stabilizer pad moving toward the driver imparts a significant force to the stop when it impacts thereon. Should either the stop pin or the weld securing the lever to the support arm fail as a result of such impact forces, the stabilizer pad will impact against the piston-rod end of the driver, ultimately causing damage thereto. Because of its size, the driver is both difficult and costly to repair or replace. Moreover, careful positioning and welding of the lever to the support arm is required to properly position the pin and increases fabrication costs of the stop and, thereby, the overall cost of the loader/backhoe.